The invention relates to actuation of downhole devices in a wellbore including actuation of downhole sampler devices.
After a wellbore has been drilled, it is desired to perform tests of formations surrounding the wellbore. Logging tests may be performed, and samples of formation fluids may be collected for chemical and physical analyses. The information collected from logging tests and analyses of properties of sampled fluids may be used to plan and develop wellbores and for determining their viability and potential performance.
Samples of fluids in a wellbore may be taken with downhole sampler devices, such as monophasic sampler devices. A sampler device may be lowered into a wellbore on a wireline cable or other carrier line (e.g., a slickline or tubing). Such a sampler device may be actuated electrically over the wireline cable after the sampler device reaches a certain depth. Once actuated, the sampler device is able to receive and collect downhole fluids. After sampling is completed, the sampler device can then be shut off and retrieved to the surface where the collected downhole fluids may be analyzed.
In some test strings, sampler devices may be attached at the end of a non-electrical cable, such as a slickline. To actuate such sampler devices, an actuating mechanism including a timer may be used. The timer may be set at the surface to expire after a set time period to automatically actuate the sampler devices. The set time period may be greater than the expected amount of time to run the test string to the desired depth.
However, a timer-controlled actuating mechanism may not provide the desired level of controllability. In some cases, the timer may expire prematurely before the test string including the sampler devices is lowered to a desired location. This may be caused by unexpected delays in assembling the test string in the wellbore. If prematurely activated, the sampler devices are typically retrieved back to the surface and the test string re-run, which may be associated with significant costs and delays in well operation.
Thus, a need exists for an improved actuation technique for sampler devices and other downhole devices and tools in a wellbore.
In general, according to one embodiment, a downhole tool includes a sampler device having one or more ports, a flow control device to control flow through the one or more ports, and an activating mechanism to control the flow control device. An assembly includes a rupture disk assembly and a fluid path between the rupture disk mechanism and the activating mechanism. The rupture disk mechanism is adapted to block communication of the fluid pressure to the activating mechanism.
In general, according to another embodiment, a tool for use in a wellbore includes one or more sampler devices and one or more activating mechanisms operatively coupled to one or more sampler devices. Each of the one or more activating mechanisms includes a pressure transducer to receive pressure pulse signals.
Other features and embodiments will become apparent from the following description, the claims, and the drawings.